The head of the United Nations children's agency, Carol Bellamy, has strongly urged the Tamil Tiger rebels not to continue with child recruitment.

Ms Bellamy said Unicef still had more than 700 complaints of child recruitment on its books.

But, speaking at the end of a three-day visit to Sri Lanka she said they did not know the total number of child soldiers.

Ms Bellamy: The true number of child soldiers is unknown

Unicef is in the process of working out a plan to return Tamil Tiger under-age recruits to their parents as part of the current peace process in Sri Lanka.

Nobody knows how many child soldiers have been recruited by the Tamil Tigers over 20 years of civil war but it probably runs into thousands.

Poverty

Boys and girls, some as young as 12, have been abducted from their homes for the war effort.

In many cases poverty has driven parents to send their children to join the rebels, confident that at least they will get fed, even if they have to risk their lives.

In some cases children volunteered, inspired by revenge for acts of violence committed by the army.

In the last year alone there have been more than 300 internationally verified cases of child recruitment by the Tigers, in violation of the ceasefire agreement they signed with the government.

Under international pressure, the Tigers have agreed to work out an action plan to release child soldiers.

Access

Unicef's executive director, Carol Bellamy, said this might involve setting up temporary transit centres for children where they could be given education and health care while their families were traced.

A group of former child soldiers in Sri Lanka

These centres would be run by the Tamil Tigers themselves, but Unicef has been promised access.

It is also likely there would be regular meetings between senior rebel commanders, ceasefire monitors and parents whose children have been abducted.

It is not clear how effective such meetings would be when child recruitment and abduction, especially in eastern Sri Lanka, are creating a climate of fear where many parents may feel too intimidated to confront rebel commanders.

Reports from the ceasefire monitors say child recruitment by the rebels is still continuing, at the same time that they are discussing the demobilisation of child soldiers.

Carol Bellamy said the rebel leadership took the position that child recruitment should not go on, but if it did it was because the lower ranks had not yet got the message.

Unicef has offered to conduct a communication campaign for the rebels to make the position of their leadership understood.

However, in southern Sri Lanka many are sceptical that a military organisation as effective as the Tamil Tigers cannot control its lower ranks and they see continued child recruitment as a sign that the rebels have little respect for democratic norms.